Milling or turning: which machine to use for your part

The most frequent doubt before machining is simple: CNC milling or conventional turning? The answer depends on the part geometry. At MASA Mecanizados (Subirats, Barcelona) we combine both processes as needed.

What CNC milling is

In a machining center the part is held still and the tool rotates and moves across several axes. Ideal for complex shapes, pockets, holes on several faces, slots and planes. If your part is not of revolution, it's almost always milling.

What turning is

In the lathe the part rotates and the tool advances linearly. The natural choice for cylindrical or revolved parts: shafts, bushings, screws, gears and stems. Conventional turning shines for one-off parts or short runs without numerical programming.

How to decide by geometry

• Revolved shape (round, symmetric): turning.
• Prisms, boxes, machined sheet: milling.
• Holes on several faces or 3D geometries: CNC milling.
• Very tight tolerances on diameter: turning, often with H7 fit.

When to combine both

Many real parts need both technologies: turn the contour and mill planes or cross holes. That's why a shop mastering both helps, as we explain in our CNC milling vs conventional turning comparison.